Originally Posted by
The Oberon
OSA, Apologies, it's an age thing. I remembered doing the initial fit at Marham before disappearing to ASI. I also remembered later aircraft having Omega and wrongly assumed that it was a dual fit.
I think it was in the ratio of a third Carousel, a third Omega, and a third standard nav fit. Turn back on a long slot with a dodgy doppler meant great reliance on the powerful ASI NDB that could be strongly influenced if there were thunderstorms about.